Fetching records with slug instead of ID

Question

I\'m currently trying to find the best way (in term of usability and performance) when dealing with a situation like fetching records tagged with a specific tag, or category

Answer 1

The first one is better, but can the slugs possibly be changed? In that case you'd need to have a redirect table (e.g. "some-article-about-dogs" is now "article-about-dogs-and-cats").

Answer 2

With the first URL style and your current db design, you can do this:

select ...
from   posts p
join   posts_to_tags pt on pt.post_id = p.post_id
join   tags t on t.id = pt.tag_id
where  t.slug = [url slug value];

As long as tags.slug is indexed, this should be very efficient, hardly any different from

select ...
from   posts p
join   posts_to_tags pt on pt.post_id = p.post_id
where  pt.tag_id = [url tag ID];